Isabella Moth

Yesterday I decided to take Raven on her daily walk in a different direction down the road for a change of pace. Our destination, instead of the abandoned property to the north, was a semi-private road to the south, that leads back through the woods to a row of mostly cottages. There aren’t any “Private Road” signs at the foot of the road, so I’m not actually sure of its status – I won’t go anywhere if there are signs posted, as there are on some such roads, but I also haven’t encountered anyone down there to ask. The road seems to see a bit of traffic even during the winter, but very little, I mostly just know this by tire tracks in the soft road surface. I feel comfortable allowing Raven to bound about off-leash there without risk of encountering cars, and it gives us another place to go when we want a change of scenery.

The day was warmer than it has been in a while, but still only a degree or two above freezing, so I was surprised to discover this Wooly Bear caterpillar crossing the road. Very slowly. I was amazed that he was moving at all, really, given how cold it was, sunshine notwithstanding. I picked him up off the road and placed him in a warm patch of sun at the base of a broad, deeply creviced tree. Hopefully he was able to climb into a nook before dark, though he surely wouldn’t have had time to make himself a cocoon.

Wooly Bears (sometimes known as Banded Wooly Bears) are the caterpillar form of the Isabella Moth (Pyrrharctia isabella). The photo above is an adult I caught at my blacklight back in June. Isabella Moths have two broods each year, one that mates in the spring and lays eggs that mature and pupate over the summer, and then these adults produce a second fall brood that overwinters as a pupa and emerges in the spring. They’ve got a wide range of foodstuffs, including birch, maple and elm, as well as various grasses, asters, clover, and others. This should make it relatively easy to raise one indoors, providing fresh food each day.

Folk lore suggests that you can tell how severe and/or long the coming winter will be by the amount of black on each end of the caterpillar’s body. Although this is largely bunk, there may be a sliver of truth to it, at least when the caterpillar is being examined close to the onset of cold weather. The red portion of the caterpillar continues to grow as it feeds and matures. Wet weather tends to stunt the development of this portion, making the black bands longer. The early onset of cold or wet weather, and therefore a longer winter, would result in a shorter red portion and longer black segments.

Unlike some fuzzy caterpillars, the hairs of Wooly Bears won’t irritate skin, so they’re safe to handle unless you have particularly sensitive skin. Of course, when you pick one up, most often it will curl into a ball for protection, “playing dead”, as it were. I was delighted to discover there are whole festivals devoted to this common caterpillar, such as the Woolybear Festival in Vermilion, Ohio, in the fall, a pre-winter equivalent to the spring tradition of Groundhog Day. According to Wikipedia, the Vermilion parade “in 2006 involved over 20 marching bands, 2,000 marchers, hundreds of animals, and over 100,000 spectators.”

I’m at my parents’ this evening, and it is chilly, unseasonably cool (it seems to me) for a mid-June night, nearly summer. I would ordinarily be outside, checking for moths on the blacklighted sheets I’d have set up, but it’s too cool for that tonight; approaching 10 C (50 F), the moths are, for the most part, tucked into sheltered spots waiting for a warmer night to fly. Since it’s June, there ought to be many nights of 20 C (68 F) temperatures that would be much more ideal. I’ve got my trap running anyway, since it involves very little effort and hey, you never know. But I’m not expecting much when I check it in the morning; the couple times I’ve peeked out the window at it I haven’t seen anything at the sheet I set up behind the light.

In contrast, earlier this month I had some excellent, warm nights. I have yet to see any nights with a sheet covered in moths, but that’s probably just as well – my identification isn’t good enough yet for me to be able to pick through the common stuff to locate the more unusual species, and I would probably feel a little overwhelmed. Even just the couple of busy-ish nights I’ve had, with 50-80 species, have been enough to keep me busy for many hours the next day. Another disadvantage to not knowing anything is that I have to photograph every moth I encounter if I want to identify it, whereas if I already know 40 of those 50 species there’s not much photographing that needs to be done the next day.

The other problem with getting so many moths is trying to choose a select few to post to the blog. With such variety, how do you narrow it down? For the non-moth’er, the large or colourful species are the obvious choices, but even among that group there is quite a selection. I eventually settled on half a dozen that I thought were the most interesting from the last few weeks. Narrowing it down to just the species I had identified helped considerably as well.

The above moth is a Wild Cherry Sphinx (Sphinx drupiferarum), which came to the blacklight at my parents’ last week. I happened to be checking the sheet as it flew in, and I knew something that large had to be a sphinx, so I really wanted to catch it. Unfortunately, I didn’t have my large-moth containers there at the sheet with me. I didn’t trust it to remain (it still hadn’t settled on the sheet, but was buzzing across its surface), so I ended up catching it in one hand, creating a loose cage with my fingers. Good thing I did, too, as it’s a somewhat uncommon species, and one that The Moth Man hadn’t seen before, so we needed photos.

On a similar note, another uncommon species that he hadn’t seen so we needed photos of was this one, the Silver-spotted Ghost Moth. The reason this species isn’t often seen is less due to its abundance, however, and more because of its habits. Most moth’ers attract their moths to some sort of lure, either a UV light or sugary syrup concoctions. This moth rarely comes to lights, so it’s infrequently caught. It has a sort of lekking behaviour, where giant swarms of males form in the evening near the species’ host trees, alders, and female moths will come to check them all out. The moths are most often encountered in these swarms. In the case of my moth, it was the rare individual that did come to check out the light, and I found it sitting in the trap. This species is also unusual in that, taxonomically, it is more closely related to the wee bitty moths than the larger moths, but it itself is about two inches long.

The caterpillar of this moth will be more familiar to most people than the moth itself. This is the adult form of the Wooly Bear caterpillar, that fuzzy, brown and black caterpillar frequently seen in the fall and perceived as a predictor of the nature of the impending winter. For such a distinct-looking caterpillar, the adult is rather bland, although its abdomen has an orange wash to it. The adults are known as Isabella Moths (Pyrrharctia isabella).

There are a number of different species of tiger moths, which are generally characterized by being about an inch in size and fuzzy, with a fuzzy caterpillar stage. The Isabella Moth is part of this group, as is the above, appropriately named the Pink-legged Tiger Moth (Spilosoma latipennis). There are two tiger moths that are nearly entirely snow white, this one and the very similar Agreeable Tiger Moth. The primary difference is in the legs – the Agreeable’s are a yellow-orange instead of pink. I’ve seen a few Agreeables so far this spring, but this was the first Pink-legged I’d caught.

Yet another bunch of tiger moths have black and tan-striped wings. This one is a Harnessed Tiger Moth. There are half a dozen or more species with this sort of pattern, and telling them apart relies on the size of the stripes, the presence of cross-bars, and the colour and pattern of the hindwings. Last week I also caught a Little Virgin Tiger Moth, very similar but for the orangeish rather than pinkish hindwings, and thinner and more numerous stripes.

When Blackburnian and I were at his mom’s place, we went for a walk through the bit of forest that backs onto her property. As we walked we kicked up many moths, about an inch in size and a bland tan colour. They were these guys, Stone-winged Owlets (Chytolita petrealis), so named for the stone colour of their wings (apparently; I think of stones as gray, not beige, personally). The long up-curved “snout” is actually a pair of palps, and are used as sensory organs. Many moths have palps, but they’re more exaggerated in some species than others.

This last one is the subtle but beautiful Unicorn Prominent (Schizura unicornis). I’m not sure why it’s been called unicorn since it has no obvious horn (unlike the previous moth). I love the shades of mocha, peach, olive and teal in the wings of this moth. I couldn’t get him to do it again for the photo, but while he was sitting in the little jar I had him in he had his hind end and wings tightly furled together and raised up in the air, like a bit of peeling bark. The prominents are a varied bunch, with some mottled like this one, others smooth and sleek, and still others rather fuzzy like the tiger moths.

As usual, if you’re interested in browsing some of the other species I’ve caught, check out my moths photoset on Flickr.

Tag: Isabella Moth

Today at Kingsford – Wooly Bear Caterpillar

A few colourful moths